This application is drawn to a process for forming aralkyl derivatives of xanthene dyes and, more particularly, to such a process wherein a previously formed xanthene dye is aralkylated.
Multicolor images formed in accordance with the principles of subtractive color photography employ yellow, magenta and cyan image forming dyes. The yellow dye ideally transmits only green and red light and absorbs only blue light and thus is sometimes referred to as "minus blue". In like manner, the magenta ("minus green") dye ideally absorbs only green light and transmits only red and blue light, and the cyan ("minus red") dye ideally absorbs only red light and transmits only green and blue light. Unfortunately, the dyes which are available for use in subtractive color photography are not "ideal" dyes but rather, tend to absorb some of the light that they ideally should transmit. This extra absorption results in less effective reproduction by the final image of one or more colors present in the original object. In particular, magenta image forming dyes typically exhibit significant absorption in the blue region.
Accordingly, there is a continuing search for new image forming dyes and, concomitantly, for new processes for preparing the dyes. The present application relates to a novel process for preparing aralkyl derivatives of xanthene dyes.